The present invention relates to a device for adjusting the elevational position of a head rest of a seat for a vehicle.
Japanese Utility Model Laid-open No. 167558/1985 discloses an example of a conventional device of this type. This device has a stay upstanding from a seat back, a guide shoe slidably engaged with the stay, a head rest body arranged on the guide shoe, and a locking mechanism arranged between the guide shoe and the stay for fastening the guide shoe to the stay at an arbitrarily elevational position.
Japanese Utility Model Laid-open No. 25258/84 discloses an example of a conventional device of other type. This device has a stay formed with a plurality of grooves along an elevational direction and upstanding on a seat back, and a locking mechanism disposed in the shell of the head rest and detachably attached to the grooves of the stay by the lateral rightward or leftward movement of the head rest.
In the device disclosed in Japanese Utility Model Laid-open No. 167558/1985, a lock releasing knob is disposed slightly lower position on the rear side of an occupant's shoulder, and two operations of releasing the lock by one hand and elevationally moving upward or downward the head rest by the other hand are required. When the head rest is adjusted elevationally upward or downward, the occupant must operate by both hands in front of the head rest. Thus, this device has a drawback that a driver has particularly a difficulty of operating the head rest during the driving operation of the vehicle.
In the device disclosed in Japanese Utility Model Laid-open No. 25258/1984, a driver can elevationally adjust the head rest even during the driving operation of the vehicle, but since only one stay is provided, it is difficult to stably move the head rest upward or downward. Further, this device has a drawback that groove rows must be formed at both sides of the stay.